IEEE Standard for Preferred Ratings,
Related Requirements, and
Application Recommendations for
Low-Voltage AC (635 V and below)
and DC (3200 V and below) Power
Circuit Breakers
This standard provides the preferred ratings for low-voltage ac (635 V and below) power circuit breakers,
fused low-voltage ac (600 V and below) power circuit breakers, general purpose dc (325 V and below)
power circuit breakers, and low-voltage dc (3200 V and below) power circuit breakers.
This standard provides preferred ratings to establish a uniform basis of product design and testing for
low-voltage ac and dc power circuit breakers. The ratings in this standard are preferred but are not
restrictive. Manufacturers may choose to offer, and users may elect to require, ratings which differ from
those in this standard.
This revision updates the preferred ratings to reflect changes in the state of the art. Ratings for some
obsolete products have been eliminated and new ratings added. This revision is coordinated with the
changes in companion standards IEEE Std C37.13™, IEEE Std C37.14™, IEEE Std C37.17™, and IEEE
Std C37.27™.